To read Exif data in json format from an image in C# use the following code:

using System.IO;
using System;
using System.Net;

class CsRethumbExample
{
    static void Main()
    {
        using (WebClient client = new WebClient())
        {
            string response = client.DownloadString("http://api.rethumb.com/v1/exif/all/http://images.rethumb.com/image_exif_1.jpg");

            Console.Write(response);

            // Use your favorite json library to parse the response!
        }
    }
}

Use the following commands to get started:

$ git clone https://github.com/rethumb/rethumb-csharp-examples.git
$ cd rethumb-csharp-examples
$ ... Use your IDE of choice to handle the file "read-exif-data-in-json.cs"